shop heat--radiant floor

If you make the floor thick enough you can lag where ever you want to. Cracking is your biggest fear, real cracks can sever the tube. have it in my garage with no problems as of yet.

Note on machine shops: A friend has it in his busy cnc shop, and they have the doors open in the moderately cold weather; all the added heat load from machines. If I were putting it in my busy shop, I might undersize or figure some other way to deal with overheating.

radiant is the best

Andrew V wrote:

If you use the aluminum tubing(Kitec) you can find it with a metal detector. The other stuff can be located with reasonable accuracy by wetting the floor and noting where it evaporates first.

I have tubing in my floor and it is awesome. I definitely recommmend it. I do not have any equipment anchored to the floor. I did place a steel subframe in the floor for a crane, but I am not sure that will ever get placed.

You could go to a thicker floor or go around the equipment. I would probably lean towards the thicker floor. With a 6+" floor you could still sink a 4" anchor directly above a tube and not have to worry about hitting a line.

JW

Another thing. I spent considerable time playing with the layout so that all loops are the same length(approximately). This eliminates the need for more expensive valves and balancing manifolds etc. I got all

JW

What sort of control system does he have? I find it hard to believe it overheats. With a proper control and understanding the hysterisis of a hydronic system it should be possible to hit a very stable and accurate heating.

JW

You'll love it. It's a great way to heat a space.

Well, you'll tie it to 6-inch wire grid, right? Lay it down, take lots of pictures, and you'll know where to miss.

When I put mine in, I was told to have it on the wire grid, about half-depth in the concrete. So, in my 5" slab, it's about there-ish. Impossible to tell where specifically, so I wouldn't count on it being deep enough. If you happen to be on a fire department and have access to the thermal imaging camera, you could use that to see exactly where the lines are. Maybe if you're in a rural area and they have one, they'd come out and do it for you in exchange for a donation of liquid refreshment?

Dave Hinz

That's what thermostatic controls at the heat source are for, no?

A metal detector works on aluminum?

That's a really good idea. Less elegant than the thermal imaging camera, but certainly cheaper.

I laid down 2" Certifoam and used the plastic chairs made for this purpose that screw into the styro to clip on the tubing. I also insulated the edge of the slab as they say that is where the biggest heat loss is. Best investment I ever made! Steve

Yes I should mention that I have 2 inch foam under my garage floor, a bit of a leap of faith but it hasn't cracked yet....spose you wouldn't think twice at pouring concrete over compacted sand, and it will squish underfoot, but foam seems wrong. If you are concerned about point loading [a punch press or something] you could insulate well[deep] around the perimeter. I loses some efficiency over insulating under but you have a large increase in thermal mass[all the dirt]

I thought that was strange too. I guess I haven't tried it. It's just something they advertise. I went with the cheap(er) stuff.

I did likewise. There is a "special" foam for this application that has a higher load rating. I dont' remember specifically. The little plastic clips make it so easy to lay out the tubing. My whole slab is insulated everywhere except for the little bit that sticks through the doorways. Couldn' t feasibly insulate that facing edge. I know there is some heat loss there, but I suspect it is minimal in comparison.

JW

Something to consider - you can also _dump_ heat into this system. In the summertime, when the sun shines into my kitchen/sunroom, I circulate water through that, and then into the basement slab. The thermometers show that I'm getting a 3 degree temperature rise in the water as it goes through the kitchen floor, which works out to heat that raises the basement floor by about 1.5 degrees. It'd dump more but the floor is well insulated from the ground underneath it. Doesn't change the overall heat picture in my house, but it does move the heat to places other than where I don't want it to be.

Dave Hinz

Typical foam insulation found in building supply houses runs from 15 to 25 PSI. It is available as high as 100 PSI compression, so there's no good reason to not use it. I installed 40 PSI stuff under my 6¼" thick floor, which has ½" rebar @ 18" centers both ways, to which I tied my heating hoses. The rebar sits on thin dobies, so the heating hoses (mine are rubber---a Heatway/Watts product) are down about 4". I run a forklift that weighs 5 tons, along with a 3 ton load, and have NO cracking aside from the original scores that were intentionally placed for controlled cracking. The rebar, which I highly recommend, prevents any settling and shifting of the cracks.

There is no better way to heat a shop---especially if you don't like cold feet.

Harold

I guess my experiences are slightly different from the rest. I put radiant floor heat in my outside shop. The tubes are on 12" centers in a 6" thick floor. Even with a very well insulated sidewall and ceiling I'm finding it takes forever to bring the shop up to heat - more than 24 hours. (I'm not in the shop all day every day) It also just isn't enough heat source for when its below 10 degrees F outside. A nearly equal size salesroom in the same barn with a standard furnace takes WAY less propane to heat and comes up to temp in 30 minutes.

In my case, I need to add a space heater and use the floor only as a supplemental heat source. Awful expensive lesson here, but it is nice to have the floor not to be an ice box.

Karl

You do not do that. Really. If it is not enough heat then either your boiler is too small or you need to put more tube in the floor. it is a design, not a guess. Did you insulate the foundation walls? IF you didn't dig up the outside and insulate to the footing.

(I'm not in

My guess is a 8 foot ceiling, 2 walls are inside walls, much easier to heat.

Propane is super expensive, and if you didn't buy an efficient boiler, it will cost you. You need a over 85 percent efficient to avoid going bankrupt.

I would do 2 things. Stop setting the shop back as severely. If it isn't drafty it ought to recover a degree and hour. It may actually cost you less than running that boiler balls out for a day to heat the place.

Change to oil. more expensive boiler, cheaper fuel. Run a primary/secondary setup using the high temp loop to run a fan forced to help speed recovery.

are the best at this stuff, some have the attitude to match....

Hmmm ... I would guess that the shop gets to and maintains the "right" temperature overnight, but then when the machines come on, heat gets added in to the shop much faster than the large thermal mass of the shop floor can cool down.